Zinc is found in both plants and animals and over 100 zinc-containing proteins and enzymes have been identified (Chaney, Textbook of Biochemistry with Clinical Correlations, pp. 1115-1147, Devlin (ed.), New York, New York, Wiley-Liss, 1992). Examples of zinc-containing enzymes include carbonic anhydrase (hydration of carbon dioxide in red blood cells), carboxypeptidase A (pancreatic peptidase), NAD-dependent dehydrogenases (alcohol dehydrogenase in liver), leucine aminopeptidase (peptidase in kidney and gastric mucosa), pyruvate carboxylase (citric acid cycle component), and leukotriene A4 hydrolase (synthesis of lipid mediators in neutrophils) (White et al., Principles of Biochemistry, New York, N.Y. McGraw-Hill Book Company, 1973). Zinc also serves as an important structural component of many proteins such as DNA binding proteins in a structure commonly termed "zinc fingers" (Schultz et al., Textbook of Biochemistry with Clinical Correlations, pp. 91-134, Devlin (ed.), New York, N.Y., Wiley-Liss, 1992).
Zinc compounds, primarily zinc salts, have shown utility in a number of areas. Examples are wound healing (Agren, Acta. Derm. Venereol. Supp. (Stockh) 154: 1-36, 1990; Pastorfide et al., Clin. Ther. 11: 258-63, 1989), healing of gastric ulcers (Frommer, Med. J. Aust. 2: 793-96, 1975), inhibition of leukotriene A4 hydrolase (prevention of the formation of lipid mediators of inflammation) (Wetterholm et al., Arch. Biochem. Biophys. 311: 263-71, 1994), and the inhibition of certain viruses such as human immunodeficiency virus (HIV) (Bridget et al., J. Med. Chem. 38: 366-78, 1995), inhibition of the HIV protease (Zhang et al., Biochemistry 30: 8717-21, 1991), herpes virus (Kumel et al., J. Gen. Virol. 71: 2989-97, 1990; Fridlender et al., Virology 84: 551-54, 1978; Gordon et al., Antimicrob. Agents Chemother. 8: 377-80, 1975), vaccinia virus (Katz et al., Antimicrob. Agents Chemother. 19: 213-17, 1981; Zaslavsky et al., J. Virol. 29: 405-48, 1979), foot and mouth disease virus (Firpo et al., Arch. Virol. 61: 175-81, 1979), and rhino virus(Korant et al., J. Virol. 71: 2989-97, 1976).
In addition to zinc(II) salts, a number of zinc(II) complexes have been made and characterized. However, in most instances such zinc(II) complexes have merely been studied to determine the coordination geometry of the metal, or luminescence thereof. For example, Jordan et al. (Inorg. Chem. 30: 4588-93, 1991) report the structural dependence of the luminescence from bis(substituted benzenethiolato) (2,9-dimethyl-1,10-phenanthroline) zinc(II) coplexes, while Monge (Acta Cryst. B33: 2329-31, 1977) reports the crystal structure of a (dicyanide)(2,9-dimethyl-1,10-phenan-throline) zinc(II) complex. Other researchers have reported zinc(II) complexes with 1,10-phenanthroline, but not for use as biologically active compounds (Fitzgerald et al., J. Chem. Soc. Dalton Trans. 141-49, 1985; Romero et al., Polyhedron 10: 197-202, 1991; Bell et al. (Inorganica Chimica Acta. 156: 205-11, 1989; Reimann et al., Inorg. Chem. 5: 1185-89, 1966; Bencini et al., Inorg. Chem. 28: 1963-69, 1989; Hu and Liu, Acta Cryst. C47: 2326-33, 1991; Cremers et al., Acta Cryst. B36: 3097-99, 1980).
While the use of zinc salts appear promising for use in certain therapeutic areas, there is still a need in the art for additional zinc-containing compounds, complexes or compositions which possess biological activity. The present invention fulfills this need, and provides further related advantages.